Revert "Issue #2227731 by _nod: Replace JSHint with ESLint for JavaScript validation."

This reverts commit 0b522f36.

.eslintrc

-{
-  "env": {
-    "browser": true
-  },
-  "globals": {
-    "Drupal": true,
-    "drupalSettings": true,
-    "domready": true,
-    "jQuery": true,
-    "_": true,
-    "matchMedia": true,
-    "Backbone": true,
-    "Modernizr": true,
-    "CKEDITOR": true
-  },
-  "rules": {
-    "eqeqeq": [2, "smart"],
-    "guard-for-in": 2,
-    "no-undef": 2,
-    //"no-unused-vars": [2, {"vars": "local", "args": "none"}],
-    "no-unused-vars": 0,
-    "strict": 2,
-    "new-cap": 0,
-    "quotes": 0,
-    "camelcase": 0,
-    "no-underscore-dangle": 0,
-    "no-new": 0,
-    "no-alert": 0,
-    "no-use-before-define": 0,
-    "consistent-return": 0,
-    "no-constant-condition": 0
-  }
-}

.eslintignore → .jshintignore

-core/assets/vendor/*
-core/modules/locale/tests/locale_test.js
+core/assets/vendor
 core/modules/tour/js/jquery.joyride-2.0.3.js
-core/vendor/*
+core/vendor
 sites/*/files

.jshintrc

+{
+  "browser"   : true,
+  "curly"     : true,
+  "eqeqeq"    : true,
+  "forin"     : true,
+  "indent"    : 2,
+  "latedef"   : true,
+  "newcap"    : true,
+  "noarg"     : true,
+  "strict"    : true,
+  "trailing"  : true,
+  "undef"     : true,
+  "unused"    : "vars",
+  "predef"    : [
+    "Drupal",
+    "drupalSettings",
+    "domready",
+    "jQuery",
+    "_",
+    "matchMedia",
+    "Backbone",
+    "Modernizr",
+    "CKEDITOR"
+  ]
+}